1. Field of the Invention
The invention relates in general to an antenna, and more particularly to a dual-band dual-antenna structure.
2. Description of the Related Art
Along with the rapid advance in computer and wireless communication technology, wireless area network (WLAN) has been widely used in people's everydayness. Nowadays, many electronic devices can be connected to the WLAN via a universal serial bus (USB) wireless network card.
However, as the wireless area network has different protocols, the corresponding operating frequency bands also vary. Thus, how to provide a USB wireless network card operated at dual operating frequency bands has become an imminent issue. As the design of electronic devices is directed towards slimness, lightweight and compactness, the size of the USB wireless network card is restricted to be as big as a USB flash drive. Under such circumstance, the size of the antenna disposed in USB wireless network card is restricted to a certain level. As a result, the operatable frequency band of the antenna is also restricted.